A device structure for detecting residual image performance and methods of making and testing the same

Abstract

The application is a device structure for detecting residual image performance and its preparation and testing method. The device is composed of two groups of comb-shaped anodes with equal light-emitting area, a cathode ring and a common cathode, or two groups of comb-shaped cathodes, an anode ring and a common anode. The two groups of comb-shaped anodes or comb-shaped cathodes are alternately arranged at equal distance with multiple same comb tooth shapes. Switches are arranged on the electrode leads of the two groups of comb-shaped anodes or comb-shaped cathodes and connected with constant current and constant voltage power supply, or the two groups of comb-shaped anodes or comb-shaped cathodes are respectively connected with two constant current and constant voltage power supplies. The electrode leads of the cathode ring and the common cathode are connected with each other, or the electrode leads of the anode ring and the common anode are connected with each other. The device structure excludes the influence of IC driving peripheral circuit, and starts from the performance of the organic structure itself to check and confirm the influence of various new organic light-emitting structures and organic materials on the residual image performance of OLED display device.

Description

Technical Field

[0001] This invention relates to the field of OLED display testing technology, specifically to a device structure for detecting OLED image retention performance, and its preparation and testing methods. Background Technology

[0002] During use, if an image is displayed continuously for a long time or the same image is displayed repeatedly in an OLED display, image retention will occur, affecting the visual experience. This phenomenon is known in the industry as image retention. The image retention performance of an OLED display is generally measured by the time it takes for the retained image to appear; a longer retention time indicates higher performance, and vice versa. The factors affecting the image retention performance of OLED displays are complex, including IC driver circuits, organic structures, and manufacturing processes. As an important component of OLED displays, determining the proportion of organic structures influencing image retention performance, effectively investigating the impact of various novel organic light-emitting structures and organic materials on image retention performance, and developing devices and their preparation and testing methods for OLED image retention performance are key areas that require understanding and attention in OLED display engineering. Currently, there is a lack of devices specifically designed for detecting image retention. Summary of the Invention

[0003] To address the lack of detection methods for OLED display image retention performance, this invention provides a method for fabricating and testing the structure of a device for detecting OLED image retention performance. This method can be used to study the driving conditions for brightness differences (i.e., image retention) and the organic light-emitting structures and process conditions that cause changes in these differences. Compared to fabricating a complete display, this method has a simpler structure, shorter fabrication cycle, and lower cost. It is beneficial for large-scale image retention testing and assessment with multiple process conditions, improving R&D efficiency, reducing production risks and R&D costs, and enhancing the economic benefits for enterprises.

[0004] The device structure for detecting OLED image retention performance is characterized by comprising two sets of comb-shaped anodes with equal luminous areas, a cathode ring, and a common cathode, or two sets of comb-shaped cathodes, an anode ring, and a common anode; the two sets of comb-shaped anodes or cathodes are arranged alternately at equal intervals with multiple identical comb teeth; each of the electrode leads of the two sets of comb-shaped anodes or cathodes is equipped with a switch connected to a constant current and constant voltage power supply, or the two sets of comb-shaped anodes or cathodes are respectively connected to two constant current and constant voltage power supplies; the electrode leads of the cathode ring and the common cathode are interconnected, or the electrode leads of the anode ring and the common anode are interconnected.

[0005] As a specific embodiment of the present invention, each comb tooth of the comb-shaped anode or comb-shaped cathode has a complete shape.

[0006] In another embodiment of the present invention, the comb teeth of the comb anode or comb cathode are divided into several sub-electrodes of the same shape and arranged at equal intervals.

[0007] Specifically, the electrode leads of the two sets of comb-shaped anodes or two sets of comb-shaped cathodes are routed with equal lengths, ensuring consistent electrode impedance and eliminating brightness differences between the two sets of electrodes caused by impedance differences during constant voltage power supply. To achieve the goal of equal length for the two sets of electrode leads, one set of electrode leads can be routed in a serpentine pattern.

[0008] Specifically, an electrode isolation layer is prepared outside the common cathode or common anode by photolithography exposure and cleaning. The electrode isolation layer is disposed between the comb-shaped anode and the common cathode, or between the comb-shaped cathode and the common anode, to prevent short circuits.

[0009] Specifically, the comb-shaped anode or common anode is selected from one or any combination of Al, Ag, Au, Ti, Cr, Ni, Nb, Ta, Mo, W, MoOx, TiOx, NiOx, ITO, IZO, ZnO, SiNx, SiOx or IGZO, with a thickness of 0.5-100 nm.

[0010] The comb-shaped cathode or common cathode is selected from any one of Mg, Ag, Yb, Ca, Na, ITO, IZO, IGZO or ZnO, with a thickness of 1-30nm.

[0011] A method for fabricating a device for detecting OLED image retention performance is characterized by fabricating two sets of electrode patterns on a substrate using photolithography or inkjet printing, and sequentially fabricating an electrode isolation layer, a comb-shaped anode or a common anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, a comb-shaped cathode or a common cathode, and a sealing film layer on the substrate.

[0012] A method for detecting OLED image retention performance, characterized by the following steps:

[0013] 1) Set the driving current or voltage value, with the current value ranging from 0.01 to 100 mA and the voltage value ranging from 0.1 V to 30 V. Simultaneously power the light-emitting areas of the two sets of comb-shaped anodes or two sets of comb-shaped cathodes, and test the brightness of each set. Adjust the brightness difference between the two sets to be less than 0.1-10%.

[0014] 2) Specify to turn off a group of power drivers, and keep the non-specified group areas continuously lit for a period of time;

[0015] 3) Turn on the power driver of the specified group, use a luminance meter to test the brightness of the two groups of areas, and adjust the power output until the brightness difference is less than 0.1-10%. Then the brightness of the two areas in the two groups is considered to be the same.

[0016] 4) Continue the above steps until the relative brightness difference between the two groups of areas is higher than 0.5-20% when tested with a luminance meter. At this point, the lighting time is recorded as the afterimage time.

[0017] This device structure eliminates the influence of peripheral IC driving circuits, focusing on the performance of the organic structure itself to investigate and confirm the impact of various novel organic light-emitting structures and organic materials on the image retention performance of OLED displays. The device has a simple structure, short fabrication cycle, and low cost, which is beneficial for high-volume image retention testing and assessment under multiple process conditions. This can improve R&D efficiency, reduce production risks and R&D costs, and enhance the economic benefits for enterprises. The method for detecting image retention performance in OLED displays using this device can be widely applied to study the driving conditions for brightness differences and the organic light-emitting structures and process conditions that cause these differences. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of Embodiment 4 of the present invention.

[0022] Among them, 1 is a comb-shaped anode, 2 is a common cathode, 3 is a constant current and constant voltage power supply, 4 is an electrode isolation layer, 5 is a comb-shaped cathode, and 6 is a common anode. Detailed Implementation

[0023] Example 1: This device includes two sets of comb-shaped anodes 1, A and B, with equal luminous areas. The comb-shaped anodes 1 are arranged alternately at equal intervals with multiple identical and complete comb-like teeth. A constant current and constant voltage power supply 3 connects the cathode to a common cathode 2 and leads out of the device. The constant current and constant voltage power supply 3 also connects the anodes of the comb-shaped anodes 1 to the leads out of the two sets of comb-shaped anodes 1. The switch of the comb-shaped anode 1 in set A is closed, and the driving current is adjusted to bring the brightness of set A to 1000 cd / m². 2 Record the driving current I1, disconnect the switch of group A and close the switch of comb anode 1 of group B, and adjust the driving current to make the brightness of group B reach 1000 cd / m². 2 Record the driving current I2. After continuously lighting group B with a constant current I2 for 10 minutes, close the switch of comb anode 1 in group A and apply driving current I1 to group A. Observe and test the brightness of areas A and B. Repeat the operation to record the change pattern of the brightness difference between areas A and B. Until the brightness difference between areas A and B measured with an imaging luminance meter is higher than 3%, the lighting time at this point is recorded as the afterimage time.

[0024] Example 2: This device includes two sets of comb-shaped anodes 1, A and B, with equal luminous areas. The comb-shaped anodes 1 of sets A and B are arranged alternately at equal intervals with multiple identical and complete comb-tooth shapes. Each comb-tooth-shaped electrode is divided into several sub-electrodes of the same shape and arranged at equal intervals. A constant current and constant voltage power supply 3 is used to connect the cathode to the lead-out electrode of a common cathode 2, and the constant current and constant voltage power supply 3 is used to connect the anode to the lead-out electrodes of sets A and B. The switch of comb-shaped anode 1 of set A is closed, and the driving voltage is adjusted to make the brightness of set A reach 1000 cd / m². 2 Record the driving voltage V1, disconnect the switch of group A and close the switch of comb anode 1 of group B, and adjust the driving voltage to make the brightness of group B reach 1000 cd / m². 2 Record the driving voltage V2. After continuously lighting group B with a constant voltage V2 for 10 minutes, close the switch of comb anode 1 in group A and apply driving voltage V1 to group A. Observe and test the brightness of areas A and B. Repeat the operation to record the change pattern of the brightness difference between areas A and B. Until the brightness difference between areas A and B is higher than 3% when tested with an imaging luminance meter, the lighting time is recorded as the afterimage time.

[0025] Example 3: This device includes two sets of comb-shaped cathodes 5, A and B, with equal luminous areas. The comb-shaped cathodes 5 are arranged alternately at equal intervals with multiple identical comb-like teeth. A constant current / constant voltage power supply 3 is used to connect the anode to a common anode 6 leading electrode, and the constant current / constant voltage power supply 3 is used to connect the cathode to the leading electrodes of the comb-shaped cathodes 5 of sets A and B. The switches of the comb-shaped cathodes 5 of sets A and B are closed, and the driving current is adjusted to achieve a brightness of 1000 cd / m². 2 Record the driving current I1, disconnect the A group switch, and adjust the driving current to make the brightness of the B group reach 1000 cd / m². 2 Record the driving current I2. After continuously illuminating group B with a constant current I2 for 10 minutes, close the switch of the comb cathode 5 in group A and apply the driving current I1. Observe and test the brightness of areas A and B. Repeat the operation to record the change pattern of the brightness difference between areas A and B. Until the brightness difference between areas A and B measured with an imaging luminance meter is higher than 3%, the illumination time is recorded as the afterimage time.

[0026] Example 4: This device includes two sets of comb-shaped cathodes 5, A and B, with equal luminous areas. The comb-shaped cathodes 5 are arranged alternately at equal intervals with multiple identical comb-tooth shapes. A constant current / constant voltage power supply 3 is used to connect the anode to a common anode 6 leading electrode, and the constant current / constant voltage power supply 3 is used to connect the cathode to the leading electrodes of the two sets of comb-shaped cathodes 5. Each comb-tooth-shaped electrode is divided into several sub-electrodes of the same shape arranged at equal intervals. The switches of the comb-shaped cathodes 5 in sets A and B are closed, and the driving voltage is adjusted to achieve a brightness of 1000 cd / m². 2Record the driving voltage V1, disconnect the A group switch, and adjust the driving voltage to make the brightness of the B group reach 1000 cd / m². 2 Record the driving voltage V2. After continuously illuminating group B with a constant voltage V2 for 10 minutes, close the switch of the comb cathode 5 in group A and apply the driving voltage V1. Observe and test the brightness of areas A and B. Repeat the operation to record the change pattern of the brightness difference between areas A and B. Until the brightness difference between areas A and B measured with an imaging luminance meter is higher than 3%, the illumination time is recorded as the afterimage time.

Claims

1. A device structure for detecting OLED image retention performance, characterized in that... The device consists of two sets of equal-sized or comb-shaped cathodes (5), an anode ring, and a common anode (6); the two sets of comb-shaped anodes (1) or comb-shaped cathodes (5) are arranged alternately at equal intervals with multiple identical comb teeth; each of the electrode leads of the two sets of comb-shaped anodes (1) or comb-shaped cathodes (5) is equipped with a switch connected to a constant current and constant voltage power supply (3), or the two sets of comb-shaped anodes (1) or comb-shaped cathodes (5) are respectively connected to two constant current and constant voltage power supplies (3); the electrode leads of the cathode ring and the common cathode (2) are interconnected, or the electrode leads of the anode ring and the common anode (6) are interconnected; each comb tooth of the comb-shaped anode (1) or comb-shaped cathode (5) has a complete shape, and each comb tooth of the comb-shaped anode (1) or comb-shaped cathode (5) is divided into several sub-electrodes of the same shape and arranged at equal intervals; the electrode leads of the two sets of comb-shaped anodes (1) or comb-shaped cathodes (5) are arranged in the form of equal-length lines.

2. The OLED image retention performance device structure as described in claim 1, characterized in that... An electrode isolation layer 4 is prepared outside the common cathode (2) or common anode (6) by photolithography exposure cleaning. The electrode isolation layer (4) is disposed between the comb anode (1) and the common cathode (2), or between the comb anode (5) and the common anode (6).

3. The OLED image retention performance device structure as described in claim 1, characterized in that... The comb-shaped anode (1) or the common anode (6) is selected from one or any combination of Al, Ag, Au, Ti, Cr, Ni, Nb, Ta, Mo, W, MoOx, TiOx, NiOx, ITO, IZO, ZnO, SiNx, SiOx or IGZO, with a thickness of 0.5-100nm.

4. The OLED image retention performance device structure as described in claim 1, characterized in that... The comb-shaped cathode (5) or the common cathode (2) can be any one of Mg, Ag, Yb, Ca, Na, ITO, IZO, IGZO or ZnO, with a thickness of 1-30nm.

5. A method for fabricating a device for detecting OLED image retention performance, based on the structure of the device for detecting OLED image retention performance according to claim 1, characterized in that... Two sets of electrode patterns are prepared on the substrate by photolithography or inkjet printing. An electrode isolation layer (4), a comb anode (1) or a common anode (6), a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, a comb cathode (5) or a common cathode (2), and a sealing film layer are sequentially prepared on the substrate.

6. A method for detecting OLED image retention performance devices, based on the structure of the OLED image retention performance device according to claim 1, characterized in that... The test is completed through the following steps: Set the driving current or voltage value, with the current value ranging from 0.01 to 100 mA and the voltage value ranging from 0.1 V to 30 V. Simultaneously power the light-emitting areas of the comb anode (1) and the comb cathode (5) electrodes of both groups A and B, and test the brightness of each group. Adjust the brightness difference between groups A and B to be less than 0.1-10%. Specify that the power supply of group A is turned off, and adjust the driving current to make the brightness of group A reach 1000 cd / m². 2 Record the driving current I1, disconnect the A group switch and close the B group switch, and adjust the driving current to make the brightness of the B group reach 1000 cd / m². 2 Record the driving current I2. After continuously lighting up group B for 10 minutes using driving current I2, close the switch of group A and apply driving current I1 to group A. Observe and test the brightness of areas A and B. Repeat the operation to record the change pattern of the brightness difference between areas A and B until the brightness difference between areas A and B is higher than 3% when tested with an imaging luminance meter. At this time, the lighting time is recorded as the afterimage time.

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